This meeting is dedicated to reviewing the critical interactions between virus and host in the pathogenesis of HIV infection. More than 20 years of basic and applied research have help to dissect the intimate relationship between HIV and its host. Since HIV targets, infects and compromises cells of the immune system, the interactions between this virus and host defenses are both especially complex and also offer key insights into mechanisms of cell biology, immune defenses and evolutionary adaptation. This Keystone symposium will focus on the mechanisms utilized by the virus for establishment of infection and propagation, protective innate and adaptive host defense mechanisms and mechanisms utilized by HIV to elude these defenses. This meeting will bring together scientists representing a number of different disciplines who have addressed these key issues. The goal of this meeting is to facilitate interdisciplinary interactions that will promote better insights into HIV disease pathogenesis and particularly to provide new investigators and students the opportunities to interact with these leaders in HIV research. [unreadable] [unreadable]